This invention relates, in general, to semiconductor devices, and more particularly, to sensor devices having a movable structure.
Conventional acceleration sensors typically include a mass that moves in response to the application of external acceleration. The motion is then converted to an electrical response so that the magnitude of the acceleration can be determined. One problem with such structures is that the movable mass can be damaged if too much acceleration is applied.
Bumpers along the outer perimeter of the movable mass is one method for preventing damage that can occur if the movable mass were to move too far. However, bumpers are not ideal in that they consume a significant amount of surface area in the sensor and they can only stop motion along one of two orthogonal axes.
Accordingly, it would be advantageous to provide a sensor structure that is capable of preventing damage to the movable mass of an accelerometer without increasing the size of the sensor.